1. Technical Field
The present disclosure relates to imaging systems and, more particularly, to an image sensor assembly for an imaging system, the image sensor assembly having an integrated photodetector array and its associated data acquisition electronics fabricated on the same substrate.
2. Background Art
In general, computed tomography (“CT”) may be utilized for a wide variety of imaging applications, such as, for example, medical imaging applications. CT imaging systems are typically configured to transmit radiation (e.g., x-rays) through a structure (e.g., a human body) to detect and/or diagnose abnormalities (e.g., tumors). In general, these low energy x-rays are subsequently received and processed to formulate an image, often three-dimensional, of the body structure that may be analyzed by users as a diagnostic aid or the like.
In general, the reception of the radiation (e.g., gamma rays or x-rays) is sometimes accomplished through the use of a device such as a detector assembly or the like. The detector assembly typically includes a plurality of structures working together to receive and process the incoming energy rays after they have passed through the body structure. For example, the detector assembly typically utilizes a scintillator assembly to convert incident radiation (e.g., x-rays) into light for detection at an array of light detection devices. In general, scintillation allows the radiation received by the scintillator assembly to be converted into useful information. The light produced by the scintillator assembly is typically received/detected and processed by a detection device/assembly (e.g., a light sensitive photodiode array), which converts the light from the scintillator assembly into an electronic signal. As such, the information from the scintillator assembly can be transferred, converted, and processed by electronic modules in a data acquisition system (“DAS”) to facilitate viewing and manipulation by users.
For example, in some CT imaging systems, an x-ray source emits a beam toward a subject or object (e.g., a patient). The beam, after being attenuated by the subject/object, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array typically produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis which ultimately produces an image.
As noted, each detector element may be characterized by a scintillator cell that releases light in response to the reception of x-rays. In general, the light is collected by a photodiode, which provides an electrical signal output that is indicative of the x-rays impinged by the scintillator cell. Charge generated from the sensed light is then transmitted to a DAS, either directly, or through a FET switch array. Some CT detectors include thousands of detector elements and, as a result, a comparable number of connections to a comparable number of detector elements share a common DAS input channel. Other known detectors provide charge storage at each pixel and share a single amplifier among many pixels.
In general, the number of pixels in a CT detector is increasing exponentially, which directly impacts the interconnect between the photodiode array and the sensitive electronics. In current CT imaging systems, the array of light detection devices (e.g., photodiodes) are attached to the electronics/electronic modules in a DAS by utilizing packaging, or wafer to wafer bonding. Stated another way, the photodiode array is fabricated on a first wafer and then attached to a second wafer having an array of electronics by wafer to wafer bonding, or the photodiode array is attached to a package with an area interconnect.
Thus, an interest exists for improved imaging systems and methods. These and other inefficiencies and opportunities for improvement are addressed and/or overcome by the systems, assemblies and methods of the present disclosure.